Control and indicating device



1951 F. L. MALTBY 2,995,105

CONTROL AND INDICATING DEVICE Filed May 14. 1959 INVENTOR. FREDERICK L2,995,105 CONTROL AND INDICATING DEVICE Frederick L. Maltby, 14'17Edgehill Road, Abington, Pa. Filed May 14, 1959, Ser. No. 813,264 1Claim. (Cl. 116-124) The present invention generally relates to acontrol knob and an adjustable dial for use with the same. Morespecifically, the present invention is concerned with 'a con trol knoband dial adapted for use with electrical components of the type adjustedby means of a rotating shaft.

A general object of the present invention is to provide a new andimproved knob and dial characterized by sirnplicity of construction andease of application.

In electrical apparatus, variable controls, such as potentiometers andcapacitors, are generally adapted for panel or chassis mounting in orderthat they may be readily adjusted. For panel or chassis mounting, suchcomponents are provided with a threaded bushing which generallysurrounds the control shaft and which is adapted to extend through ahole in the panel or chassis and be fastened thereto by a nut.

Accordingly, it is another object of the present invention to provide aknob and dial assembly which can be applied to a control element withoutspecial tools or skill and without any additional cutting of the panelor chassis on which the element is mounted.

Still another object of the present invention is to provide a dialassembly which can be applied to variable controls of the type describedin addition to or in lieu of the conventional mounting nut and providean adjustable indicating scale substantially flush with the panel orchassis.

A further object of the present invention is to provide an indicatingand control device of the type described which is operable to provide anindication of the preferred range of adjustment of the control device towhich it is applied.

Though not limited thereto, the present invention is particularlyadapted for use as a component condition.

indicator. In certain electrical equipment, circuit characteristics,such as gain, frequency of operation and the like are controlled byadjustable components. Such equipment is designed to provide thepreferred value of such characteristics within a specific range ofcomponent calibration. When the preferred value of these characteristicscan be attained only by adjusting such components beyond this limitedrange, it generally indicates component deterioration or incipientcomponent failure. It is, therefore, a still further object of thepresent invention to provide a knob and dial assembly adapted toindicate a deviation from the preferred range of component calibration.

Another further object of the present invention is to provide "a controland indicating device in which the dial may be manually shifted withrespect to the control knob and thus, easily adapted to specificapplications.

Still another object of the present invention is to provide a knob anddial assembly in which the indication of the preferred range ofcomponent calibration is adjustable with respect to the dial.

The control and indicating means of the present invention comprises aknob and dial assembly. The dial assembly includes a dial plate which isintegral with the conventional component mounting nut and adjustablewith respect thereto. The dial assembly is adapted to include fixed oradjustable calibration limits. The preferred knob configuration for usewith the dial assembly is adapted to be mounted on the control shaft ofa control element and has a annular skirt extending outward therefromadapted to substantially overlie and mask the dial plate. The d al plateand salibration are adapted to be visible through a cutout portion ofthe annular skirt which portion includes an indicating pointer.

A better understanding of the present invention may be had from thefollowing description when read with reference to the accompanyingdrawings of which:

FIG. 1 is an exploded perspective view of one embodiment of theindicating device of the present invention as applied in use;

FIG. 2 is a sectional side view taken through the midsection of the dialassembly of the indicating device shown in FIG. 1;

FIG. 3 is a side elevation of the knob shown in FIG. 1 partly brokenaway to show the set screw fastening means and that the knob is made ofan insulating ma terial; and

FIG. 4 is a perspective view of a modification of the dial assembly ofthe present invention incorporating adjustable calibration indication.

Referring now to FIG. 1, there is shown an exploded view of theindicating device of the present invention. The numeral 1 designates achassis or panel and the numeral 2 a mounting bushing of an adjustablecontrol element which extends through a hole in the chassis 1 and isadapted to be secured thereto by means of a nut. As shown, the mountingbushing 2 of the control element is concentric with the control shaft 3of the device. The indicating means of the present invention comprises adial assembly 4 and a knob 5. The dial assembly 4 is adapted to bescrewed onto the threaded mounting bushing 2 of the control element andmay be utilized in addition to the conventional mounting nut or in lieuthereof. As shown in FIG. 1, it is utilized in lieu of the conventionalmounting nut. In this respect, it should be noted that as a result ofthe novel construction of the dial assembly of the present inventionwhen utilized with the conventional mounting nut, it adds very littlethickness to the mounted assembly. By way of example, dial assemblieshaving a total thickness of /s of an inch have been constructed.Accordingly, the dial is substantially flush with the chassis or panelto which the associated control element is mounted.

Referring now to FIG. 2 in addition to FIG. 1, the dial assembly 4comprises a hexagonal mounting nut 6 having a hub portion 7, the nutforming an outwardly extending flange 26 on the hub at one end thereof.A dial plate 8 is freely mounted on the hub portion 7 and maintained infrictional contact with the flange 26 formed by the nut 6 by means of aspring washer 9 which bears against the dial plate 8. A retaining washer11 maintains the spring washer 9 in contact with the dial plate 8, andthese elements are held on the hub 7 by staking or peening the edge 12of the hub 7 to form an annular rim 2.7. By means of this construction,the dial plate 8 is rotatable with respect to the mounting nut 6 andthus, it may be readily adjusted with respect to the control elementwith which it is used. As shown, the dial plate 8 may carry suitablecalibration 13 and when utilized as a calibration limit indicator orother similar purpose, the dial plate 8 may also carry a calibrationindicating member 14 to mask critical portions of the calibration. Thecalibration indication member 14 may be in the form of a thin metalmember glued or otherwise atfixed to the dial plate 8 or it may be inthe form of a decalcomania or the like. It should be noted, however,that it is desirable that the calibration indication member 14 be of acolor contrasting with the color of the dial plate 8 in order that asetting of the control element on the preferred range be apparent to onelooking to the indicating means.

Referring also to FIG. 3, the knob 5 of the present invention has acentral bore 15 adapted to receive the control shaft 3 of the controlelement. The knob 5 is adapted to be secured to the control shaft ,3 bymeans of a set screw 16, which extends radially through its grippingportion. The knob 5 has an annular skirt 17 which extends outward fromthe gripping portion which is adapted to substantially overlie all ofthe dial plate 8 of the dial assembly 4. The innerface 18 of the knob 5is recessed at 19 to accommodate the head of the nut 6 of the dialassembly 4 when the knob is mounted on the control shaft 3. A pointer 21is provided on the knob 5 by cutting away triangular sections 22 and 23of the annular skirt 17.

For applications where it is desirable to provide for the setting of thedial plate 8 with respect to the control element on which it is mountedwithout removing the knob 5, the dial plate 8 can be made to extendslightly beyond the annular skirt 17 of the knob 5. Similarly, where itis desired not to have the dial plate adjustable once the knob ismounted, the dial plate 8 can be made slightly smaller than the annularskirt 17 of the knob 5. When the indicating means of the presentinvention is utilized as a condition indicating device, the calibrationon the dial plate 8 can be placed so as to be visible through thetriangular cutout sections 22 and 23 of the annular skirt 17. Whenutilized as a calibration limit indicator or unsafe condition indicator,the calibration indicating member 14 should also be placed so that it iscompletely masked by the annular skirt 17 of the knob 5. In this manner,the turning of the control shaft 3 by means of the knob 5 beyond thedesirable limits of adjustment, is readily apparent since thecontrasting colors of the calibration limit indicating member 14 and thedial plate 8 are visible only through the cutout sections 22 and 23 andhence, stand out in contrast with each other. The contrast can be madeeven more apparent by having the dial plate 8 and the knob 5 the samecolor. When this is done, the color pattern which exists for off limitconditions conflicts markedly with the circular single color patternpresented by the unit for normal conditions.

Referring now to FIG. 4, there is shown a modifica tion of the dialplate assembly of the present invention in which adjustable calibrationlimits are provided. This modification of the present invention issimilar to that shown in FIGS. 1 and 2 with the exception that there isrotatably mounted on the hub 7 of the mounting nut 6 a pair ofadjustable masking plates 24 and 25. As shown, the masking plates 24 and25 are mounted on the hub 7 between the dial plate 8 and the nut 6. Themasking plates 24 and 25 each have a 180 partial sector out from theirperipheries through which a portion of the dial plate is visible. Bymeans of the adjustable masking plates 24 and 25, the calibration limitsmay be separated by any amount from 0 to It should be noted that thecontrol and indicating device of the present invention, whileparticularly adapted for use with control elements of the type mountedby means of threaded bushings which is concentric with the elementcontrol shaft, it is equally suited for use with control elements havingrotatably adjusted control shafts but which are mounted by other means.In such applications, a threaded bushing having a central bore adaptedto fit over the control shaft and a shoulder adapted to bear against theback of the panel or chassis can be utilized to mount the dial plate atthe point where the shaft passes through the chassis or panel.

From the foregoing, it can be seen that the control and indicating meansof the present invention is readily adapted for application to both newand existing equipment. its application does not require skill orspecial tools. In addition, the dial assembly may be utilized inaddition to or in lieu of the conventional control element mounting nut.

Having described the present invention, what is claimed as new is:

A nut and dial assembly for use with a variable control means adjustedby means of a rotatable shaft and mounted by means of a threaded bushingconcentric with said rotatable shaft comprising, in combination, aninternally threaded nut having a cylindrical hub portion, said notforming an outwardly extending flange on said hub at one end thereof, adial freely mounted on said hub, spring means mounted on said hub andbiasing said dial against the flange formed by said nut, and an annularrim formed on the end portion of said hub opposite the flange formed bysaid nut and retaining said spring means in biasing relation to saiddial, said dial being rotatable with respect to said hub.

References Cited in the file of this patent UNITED STATES PATENTS2,043,054 Marty June 2, 1936 FOREIGN PATENTS 25,492 Australia Nov. 29,1935 405,143 Italy July 22, 1943

